Press for paper machines including screen faced roll



Nov. 7, 1933. -c. H. R. JOHNSON 1,934,543

PRESS FOR PAPER MACHINES INCLUDING SCREEN FACED ROLL Filed Nov. 30, 1932 I 2 Sheets-Sheet l Ezcfiac'z a es: 4 ,Jareen Eel Dress r g Nov. 7, 1933. c. H. R. JOHNSON 1,934,543

PRESS FOR PAPER MACHINES INCLUDING SCREEN FACED ROLL Filed Nov. 30, 1932 2 Sheets-Sheet 2 1 o uuu Jcregzz 10-: cecY rs -ss r0 Patented Nov. 7, 1933 PATENT OFFICE PRESS FOR PAPER MACHINES INCLUDING SCREEN FACED ROLL Carl Harry R. Johnson, Downingtown, Pa., assignor to Downingtown Manufacturing Company, Downingtown, Pa., a corporation of Pennsylvania Application November 30, 1932 Serial No. 645,086

22 Claims. (01. 92-49) This invention relates to a press for paper machines, and more particularly to presses which include a screen-faced roll directly engaging the paper web. Y

Where a screen-faced roll is placed in direct contact with the paper web in a paper machine, there is a tendency of the fibres of the web to gather in the face of the roll, clogging the same and interfering with operation of the roll. In many instances, it is possible to cleanse the roll by use of a spray,but in other instances the use of a spray is impossible, due to the location of the roll. Obviously, any use of a spray against a screen-faced roll contacting a dry, or nearly dry web, will tend to wet the sheet and cause crushing thereof. In these locations there is quite as much tendency to collection of fibre in the screen face of the roll, and an important object of this invention is the provision of a novel and improved means for cleansing the screen face.

A further and more specific object of the invention is the combination with a paper press including a screen-faced roll directly engaging the paper web of a felt roll engaging the screen-faced roll to remove adhering fibres therefrom.

These and other objects I attain by the construction shown in the accompanying drawings, wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention, and wherein:

Figure 1 is a semi-diagrammatic view showing.

my invention applied to an extractor press;

Fig. 2 is a similar view showing my invention as applied in a main press including a screenfaced roll;

Fig. 3 shows a modified construction of the doctor roll;

Fig. 4 is a diagrammatic view showing application of the invention to the couch roll of a plain couch in a Fourdrinier machine; Y

Fig. 5 is a similar view showing the invention as applied to a suction couch and illustrating an arrangement wherein the facings of both the doctor roll and the screen roll are trained about, rather than directly attached to, the roll; and

Fig. 6 is a diagrammatic view showing a rubberfaced roll employed as a doctor roll against a screen-faced roll.

Referring now to the drawings, and more particularly to Fig. 1 thereof, the numeral 10 generally designates a screen-facedroll of an extractor press acting dlrectly against the face of a web 11 in position upon a carrier felt 12. Such extractor rolls are, ordinarily, provided with a spray 13 for the purpose of removing fibre therefrom. In some instances where a plurality of such presses are used, the sheet is substantially dry and the spray employed must be of such character that the screen face of the roll is not too wet when it comes in contact with the sheet. Even under the most favorable circumstances, the spray 13, since it is driving the fibres against the screen, to which they have already adhered by reason of a pressing action, cannot completely remove such fibres.

In accordance with my invention, I place a doctor roll 14 in contact with the screen face of the press roll 10, this roll having a felt covering 15 which directly contacts the screen face of the press roll and maintains the contact of the felt covered roll with the press roll through any suitable means, such as a spring 16. The pressure of the felt covered roll against the screen face of the press roll is sufiicient to cause the felt surface to conform to the surface of the screen and adherently engage any fibres which may be carried by this screen face.

In a constructionof this character, the amount of water adhering to the face of the screen is suificient to keep the felt 15 moistened to such an extent that the fibres will properly adhere thereto. These fibres are then removed by means of a doctor 1'7 co-acting with the felt face of the roll.

Under circumstances where a spray is not used in conjunction with the screen-faced roll, and the paper web 11 is substantially dry, and must not be wetted, or where the screen-faced roll engages the paper web from above and, accordingly, sprayed water would pass through the roll and engage the web, an arrangement such as shown in Fig. 2 is employed. In this Fig. 2 the feltcovered roll 14 engages the screen-faced press roll 18 as in the construction of Fig. 1. Since, however, some provision must be made for dampening the felt surface in order that the adhering fibres may be properly removed from the screen face of the roll 18, a spray 19 is directed against the felt face 15 of the roll 14. In this construction, as in the construction of Fig. 1, a doctor 17 is employed to remove fibres from the felt-faced roll.

In Fig. 4 I have illustrated application of the felt-faced roll to the screen 22 of the forming section of a Fourdrinier, the roll preferably having engagement with the screen, as illustrated, during passage of the screen about the face of the couch. The illustration of this figure shows the application to a plain couch 23, and that of Fig. 5 to a suction couch 24, the result in each case being with this arrangement, it may be pointed out that while cleaning devices are employed in conjunction with Fourdrinier wires, these devices depend either upon suction or a spray to remove the adherent fibres. In, either case, those fibres which lie against the face of the wires are more firmly forced into engagement with the wires and, accordingly, there is always a certain amount of fibre passing the cleaning apparatus. The softfaced roll, penetrating as it does the face of the wire and picking the fibres therefrom, cleans the wire entirely at one face and leaves on the wire only those fibres which are so disposed that they may be readily removed by the ordinary cleaning apparatus.

It will be noted from a comparison of Figs 4 and 5 with Figs. 1, 2 and 3, that the invention is capable of use with any screen-faced r011 rather than with press rolls as in its preferred use. Such a roll could be used to advantage against the cylinder of a cylinder mold, and particularly against the cylinder of a mold with which a high head was employed, such molds ordinarily projecting from the vat sufliciently to admit of application of the doctor roll. Furthermore, while the use of felt as a facing for the roll is preferred, any soft facing material may be employed in lieu thereof; as, for example, rubber. Again, as more clearly shown in Figs. 3 and 5, this soft facing need not be directly applied to the face of the doctor roll, but may be merely trained thereabout in the form of an endless face operating over the roll and suitable guide rolls 21.

Since the construction is capable of an extremely varied application and considerable modification in its actual formation, I do not wish to be understood as limiting myself to those arrangements herein described, except as hereinafter claimed.

I claim:

1. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom.

- 2. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and means to dampen the felt facing of the roll.

3. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and.

5 5 means to dampen the felt facing'of the roll comprising a spray directed against the screen face of the press roll in advance of the point of its engagement by the felt faced roll.

4. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and means to dampen the felt facing of the roll comprising a spray directed against the felt.

5. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and a doctor engaging the felt facing of the felt-faced roll to remove fibres therefrom.

6. In combination with a press including a V screenfaced press roll directly engaging a paper web, a felt-faced r'oll engaging the screen face of the press roll to remove fibres therefrom, the

that the wire is cleaned by the roll. In connectionfelt facing of the roll being directly carried by the roll.

'7, In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and means to dampen the felt facing of the roll, the felt facing of the roll being directly carried by the roll.

8. In combination with a press including a screen-faced press roll directly engaging a paper Web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and means to dampen the felt facing of the roll comprising a spray directed against the screen face of the press roll in advance of the point of its engagement by the felt faced roll, the felt facing of the roll being directly carried by the roll.

9. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and means to dampen the felt facing of the roll comprising a spray directed against the felt, the felt facing of the roll being directly carried by the roll.

10. In combination with a press including a screen-faced press roll directly engaging a paper web, a felt-faced roll engaging the screen face of the press roll to remove fibres therefrom, and a doctor engaging the felt-facing of the felt-faced roll to remove fibres therefrom, the felt facing of the roll being directly carried by the roll.

11. In a paper machine, the combination with a roll and a screen face for the roll, said screen face directly engaging a paper web, of a softfaced roll engaging the screen face of the firstnamed roll to remove fibres therefrom.

12. In a paper machine, the combination with a roll and a screen face for the roll, said screen face directly engaging a paper web, of a soft-faced roll engaging the screen face of the first-named roll to remove fibres therefrom, the screen face of the roll being directly applied to the roll.

13. In a paper machine, the combination with a roll and a screen face for the roll, said screen face directly engaging a paper web, of a softfaced roll engaging the screen face of the firstnamed roll to remove fibres therefrom, the soft facing of the roll being directly applied to the roll.

14. In a paper machine, the combination with a roll and a screen face for the roll, said screen face directly engaging a paper web, of a soft-faced roll engaging the screen face of the first-named roll to remove fibres therefrom, the screen face of the roll being directly applied to the roll, the soft facing of the roll being directly applied to the roll.

15. In a paper machine and in combination, a roll, a traveling screen trained about the roll and a soft-faced roll having pressure engagement with the screen after separation of the paper web therefrom to remove fibres from the screen.

16. In a paper machine and in combination, a roll, a traveling screen trained about the roll and a soft-faced roll having pressure engagement with the screen after separation of the paper web therefrom to remove fibres from the screen, the soft facing of the last-named roll being directly attached to the roll.

17. In combination with a press including a roll and a screen facing moving with the roll and directly engaging a paper web, a felt faced second roll having the felt facing thereof engaging the screen facing of the press roll to remove fibres therefrom.

18. In combination with a press including a screen faced roll the face of which directly engages a paper web, a second roll and a felt facing for the second roll moving therewith and engaging the screen facing of the press roll to remove fibres therefrom.

19. In combination with a press including a roll, a screen facing moving with the roll and directly engaging a paper web, a second roll and a felt facing for the second roll moving therewith and engaging the screen facing of the press roll to remove fibres therefrom.

20. In combination with a press including a roll and a screen facing for the roll moving withthe roll and directly engaging a paper web, a second 'roll having a soft facing directly engaging the screen facing of the press roll, said facing having a greater afiinity for fibres than the screen facing of the first-named roll.

21. In combinationwith a press including a screen faced roll directly engaging a paper web, a second roll, a soft facing for the second roll moving therewith and engaging the screen face of the press roll, said soft facing having a greater affinity for fibres than the screen face of the press roll.

22. In combination with a press including a roll and a screen facing moving with the roll and directly engaging a paper web, a second roll, a soft facing for the second roll moving therewith and engaging the screen facing of the press roll, said soft facing having a greater affinity for fibres than the screen facing of the press roll.

CARL HARRY R. JOHNSON. 

